Liquid crystal displays (LCDs) employ a fluid disposed between two substrates. Each of the substrates has a transparent electrode on them. The fluid, i.e., the liquid crystal medium, is made up of various materials, such as cholesterol, cyano-biphenyl groups and so on. The chemical makeup and composition of the liquid crystal fluid is the critical element that determines the level of the applied voltage that is required to be applied to the electrodes in order to effect a change in the arrangement of the liquid crystal molecules. The applied voltage at which the liquid crystal fluid first starts to change from one state to another is known as the "off" or "threshold" voltage, and the voltage at which the change becomes complete is known as the "on" or "saturation" voltage. The various vendors of liquid crystal fluids take great care in order to precisely formulate the composition of each fluid to meet specific threshold and saturation voltages for various LCD applications. For example, an LCD used in a watch that is powered by a tiny single cell battery may have a very low driving voltage whereas an LCD used in a fixed appliance such as a refrigerator or a video cassette recorder having a much larger capacity power supply would operate at a higher driving voltage. In order to create LCDs that need this wide range of properties, the LCD manufacturers must not only stock a wide range of liquid crystal fluid compositions but each of these compositions must be carefully monitored and controlled in order to prevent any contamination that may inadvertently modify the driving voltage.
Traditionally, this problem of creating a variety of driving voltages has been solved by carefully blending various types of liquid crystal fluids together in precise formulations. Although the modern practice of chemistry is such that these formulations can be carefully controlled, this entire formulation process still contains a significant degree of art. Clearly, an improved method of providing liquid crystal LCDs with varying driving voltages would be an addition to the industry.